Need help. Weird electrical problems, now car won't run

nigel379 · 07-28-2011, 06:27 PM

So 3 weeks ago my car was running fine other than the IMA light being on.(It has been on for a while, I'll try to look up where I wrote what code it was throwing. It comes on after about 2 weeks of driving, once I clear the code)

Anyway, I was driving to work and all of a sudden the engine hesitated and then I only had IMA battery power. I coasted to the shoulder and could tell the engine was still running but the tach didn't register it. It stopped running and I restarted it to the same result. The engine idled for 5 seconds, tach not picking up, and then dies. Giving it gas doesn't increase engine speed.

Had a friend tow me rest of the way to work and I pulled the codes. The engine code was that both the TDC sensors had gone bad. Seemed logical, car didn't recognize that the engine was running. I replaced the sensors but it didn't help at all. It no longer throws an engine code but same problem.

I tried shutting off the hybrid battery using the switch in the back and I get weird results. With the battery off, the car won't start. The starter just turns over and over again. With the battery on the car starts but doesn't recognize that it runs and dies. It is a new 12v battery and I made sure every ground was clean and replaced the negative battery ground, but to no avail.

I can't figure out what the problem is. It was throwing a P1581, but now nothing. I would appreciate any ideas. Since it doesn't start using the normal starter could it be the normal starter is bad, mixed with a sensor problem? I'm lost and really need help. Thanks so much for any input.

Red18 · 07-28-2011, 09:21 PM

Engine grounds in good condition?

**AClewell** · 07-28-2011, 09:31 PM

I would go back to the simple engine testing. Does the engine have spark? Remove a coil and put an old pulg in it and ground the base of the plug while some one cranks the engine. If yes, does it have fuel? Pull a plug after trying to start it and check to see if the plug smells of gas. Does it have compression? You could pull a plug and use a compression tester to find out. It sounds like the IMA is spinning the engine but it isn't starting. Based on what you find is missing from testing will give you a direction to continue diagnosis.

nigel379 · 07-28-2011, 10:41 PM

The engine grounds have all been checked and I replaced the negative battery ground.

AClewell, thanks for the advice. With the IMA on the engine runs, you can hear it, but dies after 5 seconds. The tachometer and rest of the ecu I imagine, never recognizes that it is running. I replaced the coils and plugs last yr, so i'm sure they are good. I'll pull them and check. Fuel is a possibility, so I'll check that too. Compression is what I am most afraid of.

I am still dumbfounded at why the engine starts and runs with the IMA on but won't start with it off.

Thanks for the suggestions, guys. I really appreciate it, as I am getting very frustrated at this point.

Eli · 07-29-2011, 12:59 AM

I guess you'll just need to start going over every system? Check the origin(engine) and destination(ECU) for signal/continuity..

talonmike · 07-29-2011, 09:00 AM

Did you check for ECM codes?

Edit: I saw that you have no codes. sorry..

**AClewell** · 07-29-2011, 12:13 PM

I may be way off base, but I suspect that your engine is not actually running for that 5 seconds but that it is part of the IMA "start" cycle. When I start my car I never hold the key in the on position but just bump it to start. I assume that the IMA system takes over from there and senses when the engine is running and then stops the "start" process. The time out for the engine starting may be 5 seconds. Has anyone ever run their Insight out of gas and could elaborate on how the starting system responds? It could be as simple as a bad fuel pump.

Always check the simple things first. Dad told me that if you hear hoof beats don't expect to see Zebras.

A lot of speculation on my part here. I hope it helps you out.

Eli · 07-29-2011, 12:24 PM

The starting system responds just the same when the car runs out of gas. IMA spins it over like normal, it will start, stumble and die.

I believe him when he says the engine is running; especially since he acknowledges a difference between using the IMA and using the starter.

I wonder if a mouse chewed through the main harness or something. Definitely seems odd.

But I agree with your theme of starting simple. Check for spark, fuel pressure and then start looking at the electrical system.

**Hybrid-Battery-Repair** · 07-29-2011, 12:47 PM

Quote:

Originally Posted by nigel379

I can't figure out what the problem is. It was throwing a P1581, but now nothing.

Let me know after the engine starts running again if you still have the P1581. I'll give you the testing scripts (it may be a wiring problem, and not the battery).

**AClewell** · 07-29-2011, 01:33 PM

I just did a quick test on my car. I unhooked all the coils and hit the key, the engine sounded like it started for about 2 to 3 seconds then died. Obviously it didn't start, it was the IMA spinning the motor at about 1,000 rpms. When I reconnected the coils the engine started and went to about 1,500 rpms.

The tach signal missing is curious though. Does anyone know which sensor sends the tach signal to the PCM/Gauge?